1,181 research outputs found

    Tectonic insights of the southwest Amazon Craton from geophysical, geochemical and mineralogical data of Figueira Branca mafic-ultramafic suite, Brazil

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    This work was done with the support of the CNPq, National Council for Technological and Scientific Development – Brazil [grant numbers 443355/2014-2, 200473/2015-8, 141587/2013-0]; Peter A. Cawood acknowledges support from the Australian Research Council [grant number FL160100168].The Figueira Branca Suite is a layered mafic-ultramafic complex in the Jauru Terrane, southwest Amazon Craton. New lithological, geochemical, gamma-ray and potential field data, integrated with geological, isotope and paleomagnetic data are used to characterize this pulse of Mesoproterozoic extension-related magmatism. The Figueira Branca Suite formed through juvenile magma emplacement into the crust at 1425 Ma, coeval with the later stages of the Santa Helena Orogen. Gabbros and peridotite-gabbros display increasing enrichment of LREE, interpreted as evidence of progressive fractionation of the magma. Magnetic and gamma-ray data delimit the extent of magmatism within the suite to four bodies to the north of Indiavaí city. Modelling gravity and magnetic field data indicate that the anomalous sources are close to the surface or outcropping. These intrusions trend northwest over 8 km, with significant remanent magnetization that is consistent with published direction obtained through paleomagnetic data. The emplacement, mineralogy and geochemical signature point towards a back-arc extension tectonic framework in the later stages of the Santa Helena Orogen.PostprintPeer reviewe

    DIRECTIONS FOR SUSTAINABILITY: I. ALTERNATIVE ENERGY

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    Concern with the future of planet Earth, its sustainability and conservation of life (both human and of the several species) has resulted in several debates and socioeconomic changes in the past decades. The ongoing and systematic gas emission (especially CO2) arising out of the growing need for energy for the many social sectors has been blamed as the main villain in this story. Is it possible to go back in time and recover nature’s balance without giving up the technologies that improved the quality of life of most people in the past century? How can we control nature’s fury, consequence of the many climate changes? Answers are to be found in collaboration, once the awareness of each individual is raised via simple and clear information concerning the phenomena involved, the technology available and to be developed. In view of the above, Parque CienTec, the Science and Technology Park of the University of São Paulo, created exhibits in scale and promotes monitored activities on the type and use of the alternative energies and how to put them into practice. This study is part of a larger project involving biological sciences and social activities.Nas últimas décadas, a grande preocupação com o futuro do planeta Terra, sua sustentabilidade e a conservação da vida humana e das várias espécies, tem provocado variadas discussões e propostas de mudanças sociais e econômicas. Como principal vilã dessa história, foi eleita a intensa e contínua emissão de gases (principalmente CO2) derivada da crescente necessidade de energia pelos diversos segmentos sociais. Como retroagir no tempo para recuperar o equilíbrio da natureza sem abrir mão das tecnologias que melhoraram a qualidade de vida da maioria das populações no último século? Como estancar a fúria da natureza provocada pelas mudanças climáticas? As respostas encontram-se na colaboração após a conscientização de cada indivíduo através da informação simples e clara dos fenômenos envolvidos e das tecnologias já disponíveis e a serem desenvolvidas. Neste intuito, o Parque CienTec criou peças de exposição em escala real e promove atividades monitoradas sobre o tipo e uso de energias alternativas, de forma interativa e lúdica, para todas as idades e formações. Após um breve histórico, apresentam-se a seguir algumas alternativas e a forma de colocá-las em prática. O presente trabalho é parte de um projeto maior que envolve ciências biológicas e atividades sociais.

    Characteristics of the Alternative Phenotype of Microglia/Macrophages and its Modulation in Experimental Gliomas

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    Microglia (brain resident macrophages) accumulate in malignant gliomas and instead of initiating the anti-tumor response, they switch to a pro-invasive phenotype, support tumor growth, invasion, angiogenesis and immunosuppression by release of cytokines/chemokines and extracellular matrix proteases. Using immunofluorescence and flow cytometry, we demonstrate an early accumulation of activated microglia followed by accumulation of macrophages in experimental murine EGFP-GL261 gliomas. Those cells acquire the alternative phenotype, as evidenced by evaluation of the production of ten pro/anti-inflammatory cytokines and expression profiling of 28 genes in magnetically-sorted CD11b+ cells from tumor tissues. Furthermore, we show that infiltration of implanted gliomas by amoeboid, Iba1-positive cells can be reduced by a systematically injected cyclosporine A (CsA) two or eight days after cell inoculation. The up-regulated levels of IL-10 and GM-CSF, increased expression of genes characteristic for the alternative and pro-invasive phenotype (arg-1, mt1-mmp, cxcl14) in glioma-derived CD11b+ cells as well as enhanced angiogenesis and tumor growth were reduced in CsA-treated mice. Our findings define for the first time kinetics and biochemical characteristics of glioma-infiltrating microglia/macrophages. Inhibition of the alternative activation of tumor-infiltrating macrophages significantly reduced tumor growth. Thus, blockade of microglia/macrophage infiltration and their pro-invasive functions could be a novel therapeutic strategy in malignant gliomas

    Amyotrophic Lateral Sclerosis Multiprotein Biomarkers in Peripheral Blood Mononuclear Cells

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    Amyotrophic lateral sclerosis (ALS) is a fatal progressive motor neuron disease, for which there are still no diagnostic/prognostic test and therapy. Specific molecular biomarkers are urgently needed to facilitate clinical studies and speed up the development of effective treatments.We used a two-dimensional difference in gel electrophoresis approach to identify in easily accessible clinical samples, peripheral blood mononuclear cells (PBMC), a panel of protein biomarkers that are closely associated with ALS. Validations and a longitudinal study were performed by immunoassays on a selected number of proteins. The same proteins were also measured in PBMC and spinal cord of a G93A SOD1 transgenic rat model. We identified combinations of protein biomarkers that can distinguish, with high discriminatory power, ALS patients from healthy controls (98%), and from patients with neurological disorders that may resemble ALS (91%), between two levels of disease severity (90%), and a number of translational biomarkers, that link responses between human and animal model. We demonstrated that TDP-43, cyclophilin A and ERp57 associate with disease progression in a longitudinal study. Moreover, the protein profile changes detected in peripheral blood mononuclear cells of ALS patients are suggestive of possible intracellular pathogenic mechanisms such as endoplasmic reticulum stress, nitrative stress, disturbances in redox regulation and RNA processing.Our results indicate that PBMC multiprotein biomarkers could contribute to determine amyotrophic lateral sclerosis diagnosis, differential diagnosis, disease severity and progression, and may help to elucidate pathogenic mechanisms

    Description of two measles outbreaks in the Lazio Region, Italy (2006-2007). Importance of pockets of low vaccine coverage in sustaining the infection

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    <p>Abstract</p> <p>Background</p> <p>Despite the launch of the national plan for measles elimination, in Italy, immunization coverage remains suboptimal and outbreaks continue to occur. Two measles outbreaks, occurred in Lazio region during 2006-2007, were investigated to identify sources of infection, transmission routes, and assess operational implications for elimination of the disease.</p> <p>Methods</p> <p>Data were obtained from several sources, the routine infectious diseases surveillance system, field epidemiological investigations, and molecular genotyping of virus by the national reference laboratory.</p> <p>Results</p> <p>Overall 449 cases were reported, sustained by two different stereotypes overlapping for few months. Serotype D4 was likely imported from Romania by a Roma/Sinti family and subsequently spread to the rest of the population. Serotype B3 was responsible for the second outbreak which started in a secondary school. Pockets of low vaccine coverage individuals (Roma/Sinti communities, high school students) facilitated the reintroduction of serotypes not endemic in Italy and facilitated the measles infection to spread.</p> <p>Conclusions</p> <p>Communities with low vaccine coverage represent a more serious public health threat than do sporadic susceptible individuals. The successful elimination of measles will require additional efforts to immunize low vaccine coverage population groups, including hard-to-reach individuals, adolescents, and young adults. An enhanced surveillance systems, which includes viral genotyping to document chains of transmission, is an essential tool for evaluating strategy to control and eliminate measles</p

    Blocking TLR2 Activity Attenuates Pulmonary Metastases of Tumor

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    Background: Metastasis is the most pivotal cause of mortality in cancer patients. Immune tolerance plays a crucial role in tumor progression and metastasis. Methods and Findings: In this study, we investigated the potential roles and mechanisms of TLR2 signaling on tumor metastasis in a mouse model of intravenously injected B16 melanoma cells. Multiple subtypes of TLRs were expressed on B16 cells and several human cancer cell lines; TLR2 mediated the invasive activity of these cells. High metastatic B16 cells released more heat shock protein 60 than poor metastatic B16-F1 cells. Importantly, heat shock protein 60 released by tumor cells caused a persistent activation of TLR2 and was critical in the constitutive activation of transcription factor Stat3, leading to the release of immunosuppressive cytokines and chemokines. Moreover, targeting TLR2 markedly reduced pulmonary metastases and increased the survival of B16-bearing mice by reversing B16 cells induced immunosuppressive microenvironment and restoring tumor-killing cells such as CD8 + T cells and M1 macrophages. Combining an anti-TLR2 antibody and a cytotoxic agent, gemcitabine, provided a further improvement in the survival of tumor-bearing mice. Conclusions and Significance: Our results demonstrate that TLR2 is an attractive target against metastasis and that targeting immunosuppressive microenvironment using anti-TLR2 antibody is a novel therapeutic strategy for combating

    Impact of Continuous Axenic Cultivation in Leishmania infantum Virulence

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    Experimental infections with visceral Leishmania spp. are frequently performed referring to stationary parasite cultures that are comprised of a mixture of metacyclic and non-metacyclic parasites often with little regard to time of culture and metacyclic purification. This may lead to misleading or irreproducible experimental data. It is known that the maintenance of Leishmania spp. in vitro results in a progressive loss of virulence that can be reverted by passage in a mammalian host. In the present study, we aimed to characterize the loss of virulence in culture comparing the in vitro and in vivo infection and immunological profile of L. infantum stationary promastigotes submitted to successive periods of in vitro cultivation. To evaluate the effect of axenic in vitro culture in parasite virulence, we submitted L. infantum promastigotes to 4, 21 or 31 successive in vitro passages. Our results demonstrated a rapid and significant loss of parasite virulence when parasites are sustained in axenic culture. Strikingly, the parasite capacity to modulate macrophage activation decreased significantly with the augmentation of the number of in vitro passages. We validated these in vitro observations using an experimental murine model of infection. A significant correlation was found between higher parasite burdens and lower number of in vitro passages in infected Balb/c mice. Furthermore, we have demonstrated that the virulence deficit caused by successive in vitro passages results from an inadequate capacity to differentiate into amastigote forms. In conclusion, our data demonstrated that the use of parasites with distinct periods of axenic in vitro culture induce distinct infection rates and immunological responses and correlated this phenotype with a rapid loss of promastigote differentiation capacity. These results highlight the need for a standard operating protocol (SOP) when studying Leishmania species
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